Reusable respiratory protection device

ABSTRACT

A reusable respirator including a mask adapted for covering and conforming to the face around the nose and a mouth of a user, a strap configured to secure the mask to a face of the user, and a filter component. All components of the respirator are capable of being cleaned, disinfected and sterilized at temperatures in excess of 50° C. An outer surface of the mask is substantially smooth and wettable for easily disinfecting and is shaped with a pair of outer shield portions for housing particulate air filters. The outer shield portions each include a closeable vent through the outer surface that is adapted to provide a user seal check and direct air flow through the outer surface for filtering by the respective particulate air filter, which is adapted to filter at least 95% of airborne particles.

RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No.62/848,341, entitled “Reusable Respiratory Protection Device,” and filedon May 15, 2019, which is herein incorporated by reference in itsentirety.

STATEMENT OF FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

This invention was made with government support under Contract No.HHSO100201700032C awarded by the Department of Health and HumanServices, Office of the Assistant Secretary for Preparedness andResponse, Biomedical Advanced Research and Development Authority. Thegovernment has certain rights in the invention.

BACKGROUND 1. Field

Embodiments of this disclosure relate generally to face masks forrespiratory protection. More specifically, embodiments of thisdisclosure relate to an elastomeric half-mask respirator that preventsat least 95% of most airborne particles (most penetrating particle sizeis approximately 0.3 μm) from penetrating the mask (e.g., “N95” filterclass).

2. Related Art

Various disposable N95 filter masks intended for single use are known.Additionally, many elastomeric half-masks that are reusable have beendescribed, but these generally have one or more drawbacks that limittheir appropriate reuse in a health care setting. For example, mostexisting masks generally require replaceable filter cartridges, includeexhalation valves, may not be capable of being cleaned at hightemperatures (e.g., greater than 50° C.), are not autoclavable, containfiltration media that cannot be cleaned and/or disinfected, and/or arenot designed to limit bioburden accumulation.

SUMMARY

Embodiments of this disclosure provide an elastomeric half-maskrespirator that is reusable and adapted to filter at least 95% ofairborne particles for both non-oil-based and oil-based aerosols as wellas viable and non-viable microorganisms (e.g., N95, R95, P95, N99, R99,P99, N100, R100, P100 filter class), thereby limiting penetration ofairborne particles through the mask to less than 5% of the mostpenetrating size (e.g., 0.3 μm). Embodiments disclosed herein arecleanable at temperatures exceeding 50° C., autoclavable, designed withsurfaces that can be easily cleaned, and may be embodied in a singlepiece that includes integrated head straps and filters that do notrequire removal during cleaning, disinfection, or sterilization. Incertain embodiments, the head straps and filters are detachable andcapable of being reprocessed as separate components and/or beingreplaced. Reprocessing protocols (cleaning, disinfection, and/orsterilization) enable reusability of the respirator. In certainembodiments, a quick field reprocessing protocol enables additionalreuses between extended reprocessing protocols, which are furtherdescribed below as including more thorough reprocessing treatments(e.g., washer-disinfector, autoclave, etc.).

In an embodiment, a reusable respiratory protection device includes amask adapted for covering a portion of a user's face. The mask includesa face seal adapted to conform to a user's face around a nose and amouth of the user, an outer surface, at least one outer shield portionformed in the outer surface, and at least one closeable vent through theat least one outer shield portion. The reusable respiratory protectiondevice further includes at least one particulate air filter adapted tofilter at least 95% of airborne particles. The at least one particulateair filter is housed within the at least one outer shield portion. Theat least one closeable vent is adapted to direct air flow through theouter surface for filtering by the at least one particulate air filter.The outer surface is substantially smooth to mitigate bioburdenaccumulation and wettable to allow for cleaning, disinfection, orsterilization thereof. A strap is configured to secure the mask to theuser's face.

In another embodiment, a reusable respirator includes a unitary maskformed of a single piece of material adapted for covering a portion of auser's face. The mask includes a face seal adapted to conform to auser's face around a nose and a mouth of the user, an outer surface, afirst outer shield portion formed in the outer surface, a first ventthrough the first outer shield portion, a second outer shield portionformed in the outer surface, and a second vent through the second outershield portion. A first particulate air filter, housed within the firstouter shield portion, is adapted to filter at least 95% of airborneparticles. A second particulate air filter, housed within the secondouter shield portion, is adapted to filter at least 95% of airborneparticles. The first vent and the second vent are each adapted to directair flow to the first particulate air filter and the second particulateair filter, respectively. The outer surface of the mask is substantiallysmooth to mitigate bioburden accumulation and wettable to allow forcleaning, disinfection, or sterilization thereof.

In yet another embodiment, a method for processing a respirator forreuse includes a) providing a reusable respirator. The reusablerespirator includes a mask adapted for covering a portion of a user'sface. The mask includes a face seal adapted to conform to a user's facearound a nose and a mouth of the user, an outer surface, at least oneouter shield portion formed in the outer surface, and at least onecloseable vent through the at least one outer shield portion. At leastone particulate air filter, housed within the at least one outer shieldportion, is adapted to filter at least 95% of airborne particles. The atleast one closeable vent is adapted to direct air flow through the outersurface for filtering by the at least one particulate air filter. Theouter surface is substantially smooth and wettable to allow fordisinfection thereof. A strap is configured to secure the mask to theuser's face. The method further includes b) using the reusablerespirator in a field, and c) performing an extended reprocessingprotocol.

This summary is provided to introduce a selection of concepts in asimplified form that are further described below in the detaileddescription. This summary is not intended to identify key features oressential features of the claimed subject matter, nor is it intended tobe used to limit the scope of the claimed subject matter. Other aspectsand advantages will be apparent from the following detailed descriptionof the embodiments and the accompanying drawing figures.

BRIEF DESCRIPTION OF THE DRAWING FIGURES

Embodiments of this disclosure are described in detail below withreference to the attached drawing figures, wherein:

FIG. 1 is a first embodiment of a reusable respiratory protectiondevice;

FIG. 2 is a perspective view of the reusable respiratory protectiondevice of FIG. 1;

FIG. 3 is an exploded view of the reusable respiratory protection deviceof FIG. 1;

FIG. 4 is a perspective backside view of a mask of the reusablerespiratory protection device of FIG. 1;

FIG. 5 is a cross-sectional bottom view of the mask of the reusablerespiratory protection device of FIG. 1, in an embodiment.

FIG. 6 is another cross-sectional bottom view of the mask of thereusable respiratory protection device of FIG. 1;

FIG. 7 is a flow diagram of a respirator reuse method for a reusablerespiratory protection device, in an embodiment;

FIG. 8 shows a machine that is designed to receive the respirator forperforming the process of the invention;

FIG. 9 shows an exemplary hardware platform for certain embodiments ofthe invention;

FIG. 10 shows a second embodiment of a reusable respiratory protectiondevice; and

FIG. 11 is an exploded view showing components of the reusablerespiratory protection device of FIG. 10.

The drawing figures do not limit the invention to the specificembodiments disclosed and described herein. The drawings are notnecessarily to scale, emphasis instead being placed upon clearlyillustrating the principles of the invention.

DETAILED DESCRIPTION

The following detailed description references the accompanying drawingsthat illustrate specific embodiments in which the invention can bepracticed. The embodiments are intended to describe aspects of theinvention in sufficient detail to enable those skilled in the art topractice the invention. Other embodiments can be utilized and changescan be made without departing from the scope of the invention. Thefollowing detailed description is, therefore, not to be taken in alimiting sense. The scope of the invention is defined only by theappended claims, along with the full scope of equivalents to which suchclaims are entitled.

In this description, references to “one embodiment,” “an embodiment,”“the embodiment,” or “embodiments” mean that the feature or featuresbeing referred to are included in at least one embodiment of thetechnology. Separate references to “one embodiment,” “an embodiment,”“the embodiment,” or “embodiments” in this description do notnecessarily refer to the same embodiment and are also not mutuallyexclusive unless so stated and/or except as will be readily apparent tothose skilled in the art from the description. For example, a feature,structure, act, etc. described in one embodiment may also be included inother embodiments but is not necessarily included. Thus, the technologycan include a variety of combinations and/or integrations of theembodiments described herein.

Respirators provide respiratory protection against atmospheres withairborne respiratory hazards (e.g., particles, microorganisms, dusts,mists, oils) including viable and non-viable airborne particles.Air-purifying respirators are designed for use in an atmosphere thatprovides adequate oxygen to support life since no supplemental oxygen isprovided (as in a self-contained breathing apparatus). Respirators canbe powered or unpowered. Powered air-purifying respirators (PAPRs)supply filtered air to a mask with a positive pressure air blower thatmay or may not be breath-assisted. Non-powered air-purifying respiratorsuse the user's negative inhalation pressure to draw ambient air throughfilters to remove particulates from the ambient air and use a positivepressure exhaled from the wearer to trap any particulates that may beexhaled.

Non-powered air-purifying respirators generally fall into one of twocategories: 1) filtering facepiece respirators (FFRs), or 2) half-maskelastomeric respirators (HMERs). FFRs are generally respirators in whichthe facepiece is formed of the filter material in either a preformed“cup” style, flat fold type, or duck bill type. FFRs are generallydesigned for single use because the filter material is not wettable permanufacturer guidance, which prevents the FFR from being cleaned,disinfected or sterilized (e.g., washed or disinfected with adisinfectant solution, washer-disinfector, ultrasonicator, sterilizedvia steam autoclave, chemical sterilant, etc.) for subsequent reuse.FFRs are also constructed using materials and methods that are notintended to support reusability (e.g., durability). FFRs are lighterthan half-mask elastomeric respirators and typically discarded after asingle use to avoid acting as a fomite by spreading infectious diseases,making them preferred in health care settings. Many FFRs are approved bythe National Institute for Occupational Safety and Health (NIOSH) andcleared for use in hospital settings by the U.S. Food & DrugAdministration (FDA). During an infectious disease pandemic, such as aninfluenza or coronavirus pandemic, a large number of respirators areneeded, especially for health care workers. Single-use respirators, suchas FFRs, will quickly be consumed during a pandemic lasting weeks ormonths, thus requiring an alternative approach to stockpiling andmeeting the expected demand.

HMERs generally include a molded facepiece to which replaceablefiltering cartridges may be attached. The mask itself is reusable,whereas the filtering cartridges are generally replaceable since thefilter material cannot be cleaned or decontaminated (e.g., washed,disinfected, or steam sterilized) because they cannot be wetted permanufacturer guidance. Cleaning of HMERs in hospitals is time consuming,tedious, and prone to error for use, and they are not designed towithstand the moisture, temperature, and pressures of autoclaves andwasher-disinfectors. HMERs also contain a number of grooves, crevices,materials, and design features that render them difficult to clean.Additionally, HMERs have not been cleared for use in the medical settingby the U.S. FDA.

Embodiments of this disclosure provide a single-piece HMER that isreusable and adapted to filter at least 95% of the most penetratingairborne particles. Respirators providing at least 95% efficiency atfiltering airborne particles of the most penetrating size are referredto as being in the “P-, R-, or N95” filter class, per 42 C.F.R. Part 84.In other embodiments, the filter may be adapted to achieve higher levelsof filtration efficiency in accordance with NIOSH requirements for P-,R-, or N99 filters and/or P-, R-, or N100 filters. N-series filters arerestricted for use in environments free of oil aerosols. The R- andP-series filters are intended for removal of any particulate thatincludes oil-based liquid particulates. In addition to filtrationefficiency, embodiments of the filter will meet or exceed (e.g., lowerthan maximum value) the maximum inhalation resistance and exhalationresistance values as defined in 42 CFR Part 84. Embodiments disclosedherein differ from conventional HMERs in that the filter media can bedisinfected and/or sterilized via aqueous cleaning mechanisms(detergents, alcohol, bleach, etc.) and sterilization practices toeffectively remove and/or otherwise render inert all contaminationspecies. Certain embodiments include integrated or detachable straps,allowing the device to be donned similar to current FFRs. Certainembodiments include fixed or removable filters, allowing for integratedor separate reprocessing, respectively. The result is a sustainablyreusable fully integrated respirator meeting NIOSH requirements asdefined in 42 CFR Part 84 for a P-, R-series, or N-series filter with atleast 95% filtration efficiency (e.g., P95, P99, P100, R95, R99, R100,N95, N99, N100). Additionally, the respirator provides an assignedprotection factor greater than or equal to 10 as required forair-purifying respirators by the Occupational Safety and HealthAdministration under 29 CFR 1910.

FIG. 1 is a frontside view of an exemplary reusable respiratoryprotection device 100, which includes a mask 110 and straps 161, 162configured for wearing on a user's face. The reusable respiratoryprotection device 100 may be referred to herein as “respirator 100” forshort. The respirator 100 is an example of an elastomeric half-maskreusable respirator. Specifically, in one embodiment, the mask 110 is ahalf mask, meaning that it covers the lower half of the user's faceincluding the nose and mouth, but not the eyes. The respirator 100 isadapted to be lightweight for improved comfort, especially for healthcare workers who may wear a respirator for long durations. For example,the respirator 100 is adapted to be lighter than existing elastomerichalf-mask respirators due to the use of lighter and fewer materials. Incertain embodiments, the mask weighs between about 3-oz. to about 4-oz.In other embodiments, the mask may weigh between 2-oz.-5 oz, or lessthan 2-oz, or greater than 5-oz.

The respirator 100 is adapted to have a shelf life longer than that ofexisting N95 FFRs, which is typically three to five years, due to theuse of more durable materials and construction. In certain embodiments,the rated shelf life of respirator 100 is expected to be between ten andtwenty years.

The mask 110 and straps 161, 162 provide a substantially smoothsemi-rigid protective surface adapted for compatibility with cleaningand disinfection wiping protocols, which extends the life cycle ofrespirator 100 by allowing it to sustain numerous disinfections and/orsterilization cycles. Specifically, the mask 110 and straps 161, 162include a smooth wettable surface that is adapted to be easilycleanable. The mask 110 and straps 161, 162 lack small edges, corners,and nooks to make surfaces easily accessible for wiping withdisinfectant to avoid bioburden, such as a buildup of microorganisms.The mask 110 and straps 161, 162 are made of a material that isresistant to common disinfectants, such as isopropyl alcohol,benzalkonium chloride, hypochlorite or quaternary amines, for example.An exemplary material for the mask 110 and/or straps 161, 162 issilicone.

In one embodiment, due to the fact that the mask 110 and straps 161, 162can be molded as a single piece of material, this feature furtherenables rapid and effective cleaning since the mask 110 and straps 161,162 lack creases, bond lines, or other mechanical connections betweenseparate components that could accumulate bioburden. Specifically, themask 110 can be a unitary piece that includes a face seal 150 (describedbelow in connection with FIG. 4), a first outer shield portion 131 and asecond outer shield portion 132 formed in an outer surface of the mask110 (described below in connection with FIG. 2) and a first vent 171 anda second vent 172 through the first and second outer shields 131, 132,respectively (described below in connection with FIG. 4). The singlepiece design also enhances the ability of the respirator 100 towithstand an automated cleaning regimen for rapid and repeatedcleaning/sterilization without degradation that otherwise might initiatealong bond lines or other mechanical connections.

FIG. 2 is a perspective view of respirator 100 of FIG. 1. FIGS. 1 and 2are best viewed together with the following description. The first outershield portion 131 and the second outer shield portion 132 are portionsof the mask 110 that protrude from the front of the mask 110 on eitherside (e.g., left or right). The first and second outer shield portions131, 132 are formed as part of the material of the mask 110 and shapedto house and protect an inner filter material for purifying air (e.g.,particulate air filters 141, 142, described below in connection withFIGS. 3 and 5). Specifically, the outer shield portions 131, 132 eachforms a protective pocket for housing and protecting the inner filtermaterial (e.g., protective pockets 133, 134 described below inconnection with FIG. 6). The outer shield portions 131, 132 serve as asplashguard to protect the inner filter material from fluids that may beburdened with biological contamination (e.g., blood, saliva, andcough/sneeze droplets). The outer shield portions 131, 132 also provideprotection of the inner filter material from damage due to impact.

Straps 161, 162 provide an integrated harness for maintaining the mask110 comfortably against the user's face. The strap may be formed of asingle piece of material or two or more pieces of material. For example,as depicted in FIGS. 1-3, the strap includes an upper strap 161 and alower strap 162, but alternative strap arrangements may be employedwithout departing from the scope hereof. For example, a unitary straphaving an upper band and a lower band may be employed. An exemplarymaterial for the strap is silicone, however other elastomeric,stretchable, and/or conformable materials may be used. This enables thestrap to be stretched for assisting with donning and doffing therespirator 100, such that the strap has a first elongated length whenstretched for placing over the user's head, and a second contractedlength while being worn to securely maintain the mask 110 on the user'shead. In some embodiments, the fixed contracted length of the strap maybe adapted for a specified size range (e.g., to provide proper fit fordifferent head sizes). However, the strap may optionally include alength-adjusting feature (e.g., a gathering clip), without departingfrom the scope hereof. The strap may be attached to the mask 110 in anintegrated or detachable manner. To prevent hearing impairment, thestrap is adapted to avoid the user's ears. As further described below,the strap is adapted to be easily cleaned and sterilized together withthe mask 110 without needing to be detached. In other embodiments, thestraps can be detached for cleaning, disinfection and/or sterilization.

FIG. 3 is an exploded view of respirator 100 for viewing internalcomponents. Not all components of respirator 100 are depicted in FIG. 3for clarity of illustration. The respirator 100 includes the mask 110,the straps 161, 162, a first particulate air filter 141, and a firstfilter rim 145 adapted for holding the first particulate air filter 141.A second particulate air filter 142 and a second filter rim 146 areshown in FIG. 5. In certain embodiments, each particulate air filter141, 142 is surrounded about its circumferential edge by a respectivefilter rim 145, 146. In some embodiments, the filter rim 145, 146 may bemade of polypropylene, although other materials (e.g., silicone) may beused. In some embodiments, the particulate air filters 141, 142 and thefilter rims 145, 146 may be formed together by overmolding. Eachparticulate air filter 141, 142, secured within its respective filterrim 145, 146, can then inserted be into one of the outer shield portions131, 132 of the mask 110. The mask 110 is configured such that the outershield portions 131, 132 stretch to form a tight seal around each of theair filters 141, 142, respectively. In certain embodiments, the airfilters 141, 142 may be sealed to the mask 110 via overmolding or otherappropriate manufacturing process. Each of the air filters 141, 142, andits respective filter rim 145, 146, may be inserted into one of theouter shield portions 131, 132 of the mask 110 by hand, or by automatedmethods (e.g., robotics), or other manufacturing methods (e.g.,overmolding). In some embodiments, the air filters 141, 142 areremovable from the mask 110, but in other embodiments the air filters141, 142 are not removable.

In some embodiments, the first vent 171 provides an air passage thatconnects the first particulate air filter 141 to outside the mask 110.Similarly, the second vent 172 (see FIG. 4) provides an air passage thatconnects the second particulate air filter 142 to outside the mask 110.In one embodiment, the first and second vents 171, 172 face downwardlyand back towards the user and are further described below in connectionwith FIGS. 4-6.

In one embodiment, the first and second particulate air filters 141, 142are made of a filter media or other material adapted to purifyrespirable air by filtering airborne particles, which preventsinhalation of the particles by the user of respirator 100. The filtermedia may be pleated, with a number of pleats being adapted for improvedventilation. Pleating the media increases the filter surface area whichreduces breathing resistance. Other embodiments may use non-pleatedmedia.

In an embodiment, first and second particulate air filters 141, 142 areadapted to exceed NIOSH requirements for the P-, R-, or N95 filterclass. Other embodiments contain air filters adapted to exceed NIOSHrequirements for the P-, R-, or N99 filter class, or P-, R-, or N100filter class. In some embodiments, the particulate air filters 141, 142are adapted to meet or exceed the European EN 143 guidance requirements.The thickness of the particulate air filters 141, 142 is adapted to bethin enough to maximize the amount of pleated or non-pleated media inthe respirator to improve ventilation, lower breathing resistance, andincrease speech intelligibility. A pressure drop across the particulateair filters 141, 142 may be used to measure the relative ease ofbreathing while wearing a respirator. For example, the NIOSH-mandatedmaximum inhalational pressure drop for an N95 respirator is 25 mm-H₂O.The respirator 100 is adapted to meet or exceed (lower than max value)this maximum inhalation pressure drop even after numerouscleaning/sterilizing protocols (e.g., see the extended reprocessingprotocol Step 210, described below in connection with FIG. 7). A targetgoal of 10 mm-H₂O has been established by Project BREATHE (Radonovich L.et al., Better respiratory equipment using advanced technologies forhealthcare employees (Project B.R.E.A.T.H.E.): A report of aninteragency working group of the U.S. federal government. 2009.http://www.publichealth.va.gov/docs/cohic/projectbreathe-report-2009.pdf).In certain embodiments, the respirator 100 may be adapted to meet orexceed this goal pressure drop.

Each of the first and second particulate air filters 141, 142 mayinclude a protective coating or protective layer 147 disposed on one orboth sides of the filter media, in some embodiments. The protectivecoating/layer 147 is substantially air permeable and substantiallyhydrophobic to mitigate contamination and wetting of the filter mediafor prolonging its integrity. The protective coating/layer 147 is, forexample, a polypropylene or polyethylene layer that would protect theinner layer. In some embodiments, the filter media contains apolytetrafluoroethylene (PTFE) layer, which is substantially airpermeable and substantially hydrophobic. The PTFE layer is preferablylocated between two protective layers 147 or affixed to a singleprotective layer 147. The particulate air filters 141, 142 may includeother types of filter media, without departing from the scope hereof,such as high-efficiency particulate air (HEPA) filters and ultra-lowparticulate air (ULPA) filters or vapor capture materials (e.g.,carbon). Other types of filter media such as microglass may be usedwithout departing from the scope hereof, although a non-shedding filtermedia is preferable for durability and user safety.

In some embodiments, the first and second particulate air filters 141,142 are capable of being cleaned, disinfected, and/or sterilized. Insome embodiments, the particulate air filters 141, 142 may be cleanedwith detergents and/or enzymes using manual or automated methods. Insome embodiments, the particulate air filters 141, 142 may be cleanedusing ultrasonic baths and/or washer-disinfectors. In other embodiments,particulate air filters 141, 142 may be disinfected with isopropylalcohol, bleach, hydrogen peroxide, or other known disinfectants. Inother embodiments, particulate air filters 141, 142 may be sterilizedusing an autoclave, gamma radiation, VHP, EtO, or other knownsterilization methods. In some embodiments, the particulate air filters141, 142 may be cleaned, disinfected, and/or sterilized while stillhoused within the respirator 100. In other embodiments, particulate airfilters 141, 142 may be removed from the respirator 100 for separatecleaning, disinfecting, or sterilization.

The mask 110 may include an optional inner layer 190, in someembodiments, located between the first and/or second particulate airfilter 141, 142 and the user for reducing accumulation of breathsecretions on the first and second particulate air filters 141, 142. Theinner layer 190 may include a removable washable, flexible insert (e.g.,scrim) that provides a protective surface covering each of particulateair filters 141, 142 on the innermost portion of the mask 110 facing theuser. In other embodiments, the inner layer 190 may be provided as aunitary part of the particulate air filter 141, 142. The inner layer 190may further extend the life cycle of the respirator 100 by protectingthe filter media during disinfection, cleaning, and/or sterilizationprocesses. The inner layer 190 is composed of, for example, a flexiblemesh fabric. Exemplary materials for the inner layer 190 include, butare not limited to, polyolefin, polypropylene, polyethylene, and/orpolyphenylsulfone. Other flexible materials are also possible. The innerlayer 190 may be removably attached to the filters 141, 142, permanentlyattached to the filters 141, 142, filter overmolded, or could be astand-alone part.

In some embodiments, the respirator 100 may further include a speechdiaphragm, microphone and/or a wireless transmitter to allow a user tocommunicate better.

FIG. 4 is a perspective backside view of mask 110 of respirator 100.Upper and lower 161, 162 straps are not shown for clarity ofillustration. The face seal 150 is adapted to comfortably fit over theuser's nose and mouth and form an airtight seal against the user's face.The face seal 150 includes a main pocket 155 that encloses the user'snose and mouth and permits ample air exchange with the first and secondparticulate air filters 141, 142.

The face seal 150 includes a nose bridge 151 adapted to extend over thebridge of the user's nose and a chin pocket 152 adapted to extend belowthe user's chin, which provide the face seal 150 with a positivelocation that is stabilized by the lower strap 162 to ensure sealintegrity. The outer profile of the face seal 150 is compact below thenose so as to reduce interference with the user's field of vision and toavoid interference with eyewear (e.g., glasses) or other personalprotective equipment (e.g., face shield). The face seal 150 is adaptedto fit a large variety of different face sizes and shapes. The mask 110,including the face seal 150, may be manufactured in a variety of sizes(e.g., infant, child, small, medium, large, etc.) to provide proper fitfor different head sizes ranging from pediatric to adult head sizes. Incertain embodiments, the face seal 150 is made of silicone orthermoplastic elastomer and is adapted to reduce facial discomfort. Insome embodiments, other conformable materials may be used for the faceseal 150.

FIG. 5 is a cross-sectional bottom view of the mask 110 that shows thefirst and second particulate air filters 141, 142, which are locatedinternally within the first and second outer shield portions 131, 132 ofthe mask 110. FIG. 6 is a cross-sectional bottom view of the mask 110with the first and second particulate air filters 141, 142 shownremoved. FIGS. 5 and 6 are best viewed together with the followingdescription.

A first protective pocket 133 houses the first particulate air filter141, and a second protective pocket 134 houses the second particulateair filter 142. The first and second protective pockets 133, 134 areformed within the first and second outer shields, 131, 132,respectively.

A first gap 181 is formed between the first outer shield portion 131 andthe first particulate air filter 141, as depicted in FIGS. 5 and 6.Similarly, the second outer shield portion 132 is shaped to form asecond gap 182 between the second outer shield 132 and the secondparticulate air filter 142. The first and second gaps 181, 182 provideample space to disperse flow of air evenly across the surface of each ofthe particulate air filters 141, 142, which ensures efficient filtermedia utilization and low resistance to air flow. The first gap 181extends to the first vent 171 (e.g., see FIG. 4) to connect the airpassage to the outside. Similarly, the second gap 182 extends to thesecond vent 172 (e.g., see FIG. 4), to connect the air passage to theoutside. In one embodiment, the first vent 171 and the second vent 172are formed of a flexible material so as to be selectively closeable.Alternatively, in another embodiment, the vents 171, 172 may be a rigidopening in the outer surface of the mask for allowing airflowtherethrough.

In operation, as a user of respirator 100 inhales, air is drawn into themask 110 via the first and second vents 171, 172, through respectivefirst and second gaps 181, 182, and across respective first and secondparticulate air filters 141, 142. Particles in the air are filtered bythe first and second particulate air filters 141, 142, and purified airis delivered to the main pocket 155 within mask 110 for inhalation bythe user. When exhaling, the exhaled breath of the user passes in theopposite direction through the air filters 141, 142 across the gaps 181,182, and out of the mask 110 via the vents 171, 172.

The mask 110 includes a built-in user seal check method adapted for theuser of the respirator 100 to ensure facial seal integrity with the mask110. The user seal check method allows the user of the respirator 100 totest that the face seal 150 provides a proper airtight seal before usingthe respirator 100 in the field. Along an underside of the first andsecond outer shield portions 131, 132, where the first and second vents171, 172 are formed, the mask 110 is adapted to be flexible, thusenabling temporary closure of the vents.

To test the seal, the outer shield portions 131, 132 can each bedeflected inward against the outer surface of the mask 110 totemporarily close the closeable vents 171, 172. Specifically, the userpresses inwardly (e.g., with a finger) on the outer-lower region of thefirst outer shield portion 131 in such a manner that the first vent 171closes. Similarly, the user presses inwardly (e.g., with another finger)on the outer-lower region of the second outer shield portion 132 in sucha manner that the second vent 172 closes. With both of the vents 171,172 simultaneously closed, the user inhales, and if a proper airtightseal is formed, a slight inhalation vacuum results, which pulls the maskagainst the user's face confirming a proper facial seal. Otherwise, if aleak exists along the face seal 150, the user can detect the leak as airrushes in against the user's face and a lack of vacuum upon inhalation.Upon release of the lower region of the first and second outer shieldportions 131, 132, the first and second vents 171, 172, respectively,return to their original shape. This re-opens the vents 171, 172,providing ports for air exchange with the first and second particulateair filters 141, 142, respectively.

FIG. 7 is a flow diagram of an exemplary respirator reuse method 200adapted for reuse of respirator 100 or respirator 300 (see FIGS. 8 and 9and their description below). Respirators 100 and 300 are adapted forcleaning, disinfection, and/or sterilization using a variety ofprotocols, which may be employed in various combinations to increase thenumber of reuses, as described below in connection with FIG. 7. Althoughthe below protocols are discussed with respect to respirator 100,similar protocols could be performed on respirator 300.

Embodiments may include performing a high-level sterilization processthat includes cleaning the respirator 100 followed by autoclavetreatment. Other sterilization processes such as vaporized hydrogenperoxide, ethylene oxide, gamma irradiation, etc. are envisioned.Embodiments may include performing a disinfection process that includescleaning the respirator 100 followed by disinfection viawasher-disinfector, chemical disinfection, heat disinfection, etc.Embodiments may include performing a quick field reprocessing protocol,which may include manually cleaning and disinfecting the respirator 100,300 by an operator or assigned staff.

More specifically, in Step 210, an extended reprocessing protocol isperformed. In one embodiment, the extended reprocessing protocol 210involves cleaning, disinfecting and/or sterilizing steps usingspecialized equipment that may be found in a hospital or other healthcare setting, such as an autoclave, washer-disinfector, gamma radiation,VHP, EtO, ultrasonic bath, etc. The respirator 100 is adapted to befully autoclavable, cleanable, and/or disinfectable as a single unit(e.g., without requiring any disassembly and reassembly), including withthe first and second particulate air filters 141, 142, as well as withthe upper and lower straps 161, 162 attached.

In certain embodiments, the first and second particulate air filters141, 142, as well as the upper and lower straps 161, 162 may bedisassembled and processed separately using the extended reprocessingprotocol of Step 210. In an example of Step 210, the respirator 100 issubjected to a cleaning and/or disinfecting step in a washer-disinfectorat about >50° C. or an ultrasonic bath after retrieval from the field(see Step 240, described below); and then followingwashing/cleaning/disinfecting, the respirator 100 is subjected toautoclaving (e.g., steam sterilization application of high temperatureand pressure) for a predetermined duration. The order of thecleaning/disinfecting and autoclaving steps may be reversed in someembodiments. In some embodiments, a pre-rinse to the respirator may beincluded. An exemplary extended reprocessing protocol is an OSHAprotocol defined under 29 CFR 1910.134. Another embodiment of thecleaning and sterilization process allows the respirator to bedisassembled and each part undergoes a separate cleaning andsterilization process.

As an alternative to above-described processing methods, the extendedreprocessing protocol 210 may include cleaning and drying the respirator100 at home for personal reuse using a washing machine or dishwasher,and then a residential dryer if necessary.

Reuse of the filter media following cleaning/disinfection/sterilizationprocessing is an advantage for the reusability of the respirator 100. Agreater number of reuses provides a lower cost per use, reduces the needfor stockpiling of respirators in preparation for a pandemic, andmaintains availability of clean respirators during a pandemic. Incertain embodiments, the extended reprocessing protocol of Step 210enables safe reuse of respirator 100 for at least one hundred reuses.

In Step 220, the respirator 100 is used in the field. In an example ofStep 220, the respirator 100 is deployed for use in the field afterextended reprocessing protocol 210. In another example of Step 220, therespirator 100 is deployed for use in the field after a quick fieldreprocessing protocol is performed (see Step 230, described below). Herethe term “field” is meant to broadly include any indoor or outdoorlocation where the respirator 100 may be worn by a user, including butnot limited to hospitals, clinics, other occupational settings, homes,businesses, parks, gyms, and while traveling via transportation vehicles(e.g., airplanes, ships, trains, automobiles, bicycles, scooters, etc.).

In Step 230, a quick field reprocessing protocol is performed. In anexample of Step 230, the respirator 100 is wiped down with adisinfectant material or a disinfecting wipe. In another example of Step230, at least a portion of the respirator 100 is cleaned with adetergent, then disinfected with a wipe or spray. In some embodiments,only the exterior surfaces of the mask 110 (including those surfacesfacing the user) are cleaned/disinfected. In other embodiments, the mask110 and straps 161, 162 are cleaned/disinfected. In some embodiments,the respirator 100 may be disinfected with isopropyl alcohol, bleach,hydrogen peroxide, or other known disinfectants. The quick fieldreprocessing protocol may be quickly performed (e.g., in less than oneminute) without needing specialized cleaning equipment such as anautoclave, washer-disinfector, or ultrasonic bath. The quick fieldreprocessing protocol is intended to be performed a predetermined numberof times (e.g., five or more) to provide a limited number of reusesbefore performing the extended reprocessing protocol referenced in Step210.

The quick field reprocessing protocol may include steps intended toensure adequate disinfection based on standard-operating-procedures thatadhere to tested and well-defined health care practices. For example,the quick field reprocessing protocol may stipulate an appropriatedisinfectant, a preferred sequence of surfaces to wipe, a sufficientduration for wiping and a sufficient contact time of the disinfectant.The quick field reprocessing protocol may stipulate steps for the safetyof the person performing the protocol, such as instructions for wearingsafety gloves, a lab coat, safety glasses, etc. Additionally, the quickfield reprocessing protocol may stipulate steps for appropriate disposalof the wipes (e.g., instructions regarding local regulations for thehandling and disposal of biohazardous waste). The quick fieldreprocessing protocol 230 may be performed while the respirator is wornby the user. Due to the smooth wipeable surfaces of the mask 110 andstraps 161, 162, the user is able to easily wipe down the mask 110 priorto donning and doffing to mitigate self-contamination.

Following Step 230, the respirator reuse method 200 returns to Step 220for reusing the respirator in the field. The respirator reuse method 200is intended to proceed back and forth between Step 220 and Step 230 alimited number of times before the respirator reuse method 200 proceedswith Step 240, described below, for retrieval of the respirator 100 fromthe field. The number of uses (in Step 220) and optionally the number ofsubsequent quick field reprocessing protocols (in Step 230) that areperformed in between extended reprocessing protocols (in Step 210) maybe tracked as part of a use monitoring program, as further describedbelow in connection with Step 250. Alternatively, the respirator reusemethod may be performed without Step 230 entirely.

When Step 210 and Step 230 are both performed, the number of quick fieldreprocessing protocols between each extended reprocessing protocolresults is a multiplier of the available number of uses. For example, ifthe respirator 100 is processed by the quick field reprocessing protocol230 five times between each extended reprocessing protocol 210, therespirator 100 would be then be able to be used six hundred times ratherthan one hundred.

In Step 240, the respirator is retrieved from the field. The respiratormay be retrieved from the field after a predetermined number (e.g.,five) of quick-field disinfections, or fewer/longer, as performed inStep 230. In an example of Step 240, a health care worker turns in theirrespirator 100 to a health care facility equipped with specializedequipment for performing an extended reprocessing protocol in Step 210.In an example of Step 240 for personal use, a user places the respirator100 in a home dishwasher or home washing machine for cleaning in Step210.

In an optional Step 250, monitoring the use and reprocessing of therespirator is performed for the purposes of life cycle management. In anexample of Step 250, the respirator 100 is tracked as part of a usemonitoring program. An identification tag 105, shown in FIGS. 2 and 3,may be attached to the respirator 100 for quickly identifying individualrespirators as part of the use monitoring program. An example of theidentification tag 105 is a scannable identification tag, including butnot limited to a barcode or a radio-frequency identification (RFID) tag,which may be scanned with a scanning device for quickly identifying arespirator 100 and indicating its current use category. The barcode maybe a one-dimensional (1D) barcode, a two-dimensional (2D), or a matrixbarcode such as a Quick Response (QR) code. Alternatively, a RFID tagmay be attached to, or embedded within, the respirator 100 foridentifying each respirator unit (e.g., via a serial number) and fortracking its use and disinfection. Other types of tracking devices ormarkers 105 may also be used.

For example, in connection with Step 210, following completion of theextended reprocessing protocol, or optionally at intermediate stepsthroughout the reprocessing protocol, individual respirators 100 arescanned for tracking their status via a processor within a database. Usemonitoring may be performed in connection with any of the steps of therespirator reuse method 200. For example, following each use in thefield (Step 220), and/or following each quick field reprocessingprotocol (Step 230), and/or following each extended reprocessingprotocol 210, and/or following retrieval of the respirator (Step 240),respirator 100 may be scanned for updating the database accordingly. Thedatabase may also be accessed from a mobile device (e.g., smartphone ortablet) for remotely updating information (e.g., to indicate that aquick field reprocessing protocol 230 has been performed in the field).

The extended reprocessing protocol 200 may be manual or automated. Forexample, batch processing of a plurality of respirators may beaccomplished by a machine-automated process.

FIG. 8 shows an embodiment of a machine 500 designed to receive therespirator 100 for the extended reprocessing protocol 210. Machine 500may include a first stage 502 where disinfection/cleaning is performed,an optional holding area 504, a second stage 506 wherein sterilizationis performed.

In some embodiments, the disinfection machine 500 may include a trackinginterface 508 that cooperates with an identification tag 105 on therespirator to indicate that a disinfection cycle has been performed. Thetracking interface 508 may cooperate with a computer 510 that may haveat least one processor, a graphical user interface, an input device, anda display for allowing the user to track the disinfection process.Tracking may include the number of times the disinfection has beenperformed on the particular personal protective equipment (PPE), thelocations where the PPE has been used, and the identification of usersof the PPE. The computer 510 may optionally interface with an inventorymanagement system for assisting with inventory management andpurchasing.

The computer 510 may also allow a user to control all aspects of theprocess, including the predetermined amounts of time for each of thesteps, the desired concentrations for any disinfecting solutions beingapplied, a temperature for sterilization, and the type of sterilizationto be applied. The machine 500 is capable of processing one respiratoror a plurality of respirators simultaneously. The machine 500 mayinclude a bar-code reader or other scanner or tracking device forreceiving information from each respirator to be treated, which may beread from an indicator, such as identification tag 105.

For purposes of life cycle management of the respirator, the machine 500may manually receive the age of the respirator from the operator or mayautomatically detect the age of the respirator. The machine 500 mayinclude an automatic detection mechanism for determining the age of therespirator, such as by a spectral scan of the material, a measurement ofthe off-gassing or volatile materials, or a particular response to thedisinfection process. The machine 500 may alternatively or additionallydetect the age of the PPE from identification tag 105 on the respirator,which may be cross-referenced with a database tracking system. Themachine 500 may alternatively or additionally use the identification tag105 to correlate the number of allowable disinfection cycles with alook-up table containing the useful life for various respirator andcontamination levels/types. The machine 500 may include a mechanism forproviding an alert, which may be visual and/or audio, when therespirator has exceeded the allowable number of disinfection cycles.

The disinfection machine 500 may include racks designed to support therespirator such that all outer surfaces can be evenly treated during theprocess. The racks may be extendable and/or interchangeable depending onwhat type/size of respirator is to be disinfected. The machine 500 mayinclude hooks for hanging the straps of the respirator thereon.

In some embodiments, central computer 510 that is part of machine 500described in reference to FIG. 8 may be a computer 702 as described withreference to FIG. 9.

FIG. 9 shows an exemplary hardware platform for certain embodiments ofthe invention. Computer 702 can be a desktop computer, a laptopcomputer, a server computer, a mobile device such as a smartphone ortablet, or any other form factor of general- or special-purposecomputing device. Depicted with computer 702 are several components, forillustrative purposes. In some embodiments, certain components may bearranged differently or absent. Additional components may also bepresent. Included in computer 702 is system bus 704, whereby othercomponents of computer 702 can communicate with each other. In certainembodiments, there may be multiple busses or components may communicatewith each other directly. Connected to system bus 704 is centralprocessing unit (CPU) 706. Also attached to system bus 704 are one ormore random-access memory (RAM) modules 708. Also attached to system bus704 is graphics card 710. In some embodiments, graphics card 710 may notbe a physically separate card, but rather may be integrated into themotherboard or the CPU 706. In some embodiments, graphics card 710 has aseparate graphics-processing unit (GPU) 712, which can be used forgraphics processing or for general purpose computing (GPGPU). Also ongraphics card 710 is GPU memory 714. Connected (directly or indirectly)to graphics card 710 is display 716 for user interaction. In someembodiments, no display is present, while in others it is integratedinto computer 702. Similarly, peripherals such as keyboard 718 and mouse720 are connected to system bus 704. Like display 716, these peripheralsmay be integrated into computer 702 or absent. Also connected to systembus 704 is local storage 722, which may be any form of computer-readablemedia and may be internally installed in computer 702 or externally andremovably attached.

Computer-readable media include both volatile and nonvolatile media,removable and nonremovable media, and contemplate media readable by adatabase. For example, computer-readable media include (but are notlimited to) RAM, ROM, EEPROM, flash memory or other memory technology,CD-ROM, digital versatile discs (DVD), holographic media or otheroptical disc storage, magnetic cassettes, magnetic tape, magnetic diskstorage, and other magnetic storage devices. These technologies canstore data temporarily or permanently. However, unless explicitlyspecified otherwise, the term “computer-readable media” should not beconstrued to include physical, but transitory, forms of signaltransmission such as radio broadcasts, electrical signals through awire, or light pulses through a fiber-optic cable. Examples of storedinformation include computer-usable instructions, data structures,program modules, and other data representations.

Finally, network interface card (NIC) 724 is also attached to system bus704 and allows computer 702 to communicate over a network such asnetwork 726. NIC 724 can be any form of network interface known in theart, such as Ethernet, ATM, fiber, Bluetooth, or Wi-Fi (i.e., the IEEE802.11 family of standards). NIC 724 connects computer 702 to localnetwork 726, which may also include one or more other computers, such ascomputer 728, and network storage, such as data store 730. Generally, adata store such as data store 730 may be any repository from whichinformation can be stored and retrieved as needed. Examples of datastores include relational or object-oriented databases, spreadsheets,file systems, flat files, directory services such as LDAP and ActiveDirectory, or email storage systems. A data store may be accessible viaa complex API (such as, for example, Structured Query Language), asimple API providing only read, write and seek operations, or any levelof complexity in between. Some data stores may additionally providemanagement functions for data sets stored therein such as backup orversioning. Data stores can be local to a single computer such ascomputer 728, accessible on a local network such as local network 726,or remotely accessible over Internet 732. Local network 726 is in turnconnected to Internet 732, which connects many networks such as localnetwork 726, remote network 734 or directly attached computers such ascomputer 736. In some embodiments, computer 702 can itself be directlyconnected to Internet 732. Additionally, instructions to perform any ofthe steps described in reference to FIG. 7 may be stored on the localstorage 722.

FIG. 10 shows a second embodiment of an exemplary reusable respiratoryprotection device 300 having a mask 310 and a strap 360. The reusablerespiratory protection device 300 may be referred to herein as“respirator 300” for short. The respirator 300 may be similar torespirator 100, FIG. 1. For example, the mask 310 is also a half maskthat covers the lower portion of the user's face including the nose andmouth but not the eyes. The respirator 300 is also adapted to belightweight for improved comfort (e.g., between about 3-oz. to about4-oz).

A frame 320 provides structural support for other components and one ormore attachment points for the strap 360. A pair of outer shieldportions 330 each serve as a splashguard that protect an inner filtermaterial, such as particulate air filters 340 (see FIG. 9) fromcontamination. Each outer shield portion 330 is positioned on one side(e.g., left or right) of the mask 310. A plurality of vents 331 arepositioned along the edge of each outer shield portion 330 for allowingair passage to and from the particulate air filters 340. Not all vents331 are enumerated in FIGS. 10 and 11 for clarity of illustration. Theouter shield portions 330 are compatible with reprocessing protocols,such as the quick field reprocessing protocol 230, described above inconnection with FIG. 7. A face seal 350 provides an airtight sealagainst the wearer's face.

FIG. 11 shows an exploded view of the respirator 300 of the embodimentof FIG. 8. The exploded view provides separation between components ofthe respirator 300 for clarity of illustration. In addition to thecomponents depicted in FIG. 10, FIG. 11 illustrates a particulate airfilter 340 and a filter rim 345 adapted for holding the particulate airfilters 340. An optional inner shield 335 may be used in someembodiments for protecting an inner side of the particulate air filters340, as further described below. In certain embodiments, the particulateair filters 340 may include a pair of air filters 340 each adapted for aleft and right side of mask 310, respectively. Likewise, the optionalinner shield 335 may include a pair of inner shields 335 each adaptedfor a respective side of mask 310.

The face seal 350 includes a nose bridge that extends over the bridge ofthe wearer's nose and a chin pocket that extends below the wearer'schin, which provide the face seal 350 with a positive location that isstabilized by the strap 360 to ensure seal integrity.

In certain embodiments, the frame 320 includes a pair of frames eachadapted for supporting one of the pair of particulate air filters 340and one of the pair of outer shield portions 330, respectively. However,in some embodiments, the frame 320 is molded as a single component.During manufacture of the mask 310, the filter rim 345 is overmoldedwith the frame 320 encapsulating the particulate air filters 340. Theouter shield portions 330 are coupled with the frame 320 (e.g.,overmolded or snap-in) for protecting the outer side of the particulateair filters 340.

The outer shield portions 330 include a substantially smooth surfaceadapted for protecting the particulate air filters 340 and for beingwettable and washable. Each outer shield portion 330 is raised above theparticulate air filter 340 creating a gap between the outer shieldportion 330 and the frame 320 with an ample plenum incorporated on theunderside of the outer shield portion 330 to disperse flow evenly acrossthe surface of the particulate air filters 340 ensuring efficient filtermedia utilization and low resistance. The plurality of vents 331 provideports for passage of air from outside the respirator 330 to the spacebehind each outer shield 330.

Each outer shield portion 330 provides a semi-rigid protective surfacefor covering the underlying particulate air filter 340. An exemplarymaterial for the outer shield portion 330 is silicone. The outer shieldportion 330 is also wettable and resistant to common disinfectants, suchas benzalkonium chloride, hypochlorite or quaternary amines, forexample.

In general, during wash and disinfecting cycles, mechanical stressplaced on filter media when fully exposed to the forces of the washingcycle reduce the filter media life. The outer shield portions 330 notonly provide protection from biological fluid contamination (e.g.,blood, saliva, and cough/sneeze droplets), the outer shield portions 330also increase the number of wash cycles that the underlying particulateair filters 340 can withstand, extending the life cycle of therespirator 300. The outer shield portion 330 also enables a simplifiedcleaning process, including automated cleaning regimens.

The particulate air filter 340 may be similar to the first particulateair filter 141 of FIG. 3. The filter rim 345 is configured to hold atleast one particulate air filter 340. In some embodiments, the filterrim 345 is adapted to hold a pair of particulate air filters 340, one onthe left side of the mask 310 and another on the right side of the mask310. In some embodiments, the filter rim 345 is adapted to encapsulatefour particulate air filters 340, a top-left, a top-right, abottom-left, and a bottom-right particulate air filter. Otherconfigurations of the filters are possible.

The filter rim 345 and the frame 320 may be molded separately orovermolded together in one step with one or more particulate air filters340 encapsulated therein. In certain embodiments, each particulate airfilter 340 includes a polytetrafluoroethylene (PTFE) filter media havingat least one layer of PTFE. In some embodiments, the particulate airfilter 340 may include other types of filter media, such ashigh-efficiency particulate air (HEPA) filters and ultra-low particulateair (ULPA) filters. Other types of filter media such as microglass maybe used without departing from the scope hereof, although a non-sheddingfilter media is preferable for durability.

Similar to the first and second particulate air filters 141, 142, theparticulate air filter 340 is adapted to exceed NIOSH requirements forthe N95 filter class after performing numerous reprocessing protocols.The thickness of the particulate air filter 340 is adapted to be thinenough for improved ventilation, lower breathing resistance, and speechintelligibility.

The optional pair of inner shields 335 provide a washable, flexibleinsert (e.g., a scrim) that provides a protective surface covering thepair of particulate air filters 340, respectively. The optional innershields 335 extend the life cycle of the respirator by protecting thefilter media during automated cleaning processes.

The face seal 350 is similar to the face seal 150 of FIG. 1 and designedto comfortably fit over the wearer's nose and mouth and form an airtightseal. In certain embodiments, the face seal 350 is made of silicone andis adapted to reduce facial pressure and discomfort.

The face seal 350 includes a built-in user seal check method. The userseal check method is adapted for a wearer of the respirator 300 to testthat the face seal 350 provides a proper airtight seal. In oneembodiment, the pair of outer shield portions 330 are each adapted to becollapsible against a respective particulate air filter 340, providing aseal against the respective air filter 340, which allows the user sealtest to be performed. Each outer shield portion 330 is flexible enoughto be pushed into a collapsed configuration to create a seal whenneeded. The user then tests the seal by inhaling slightly to confirm agood facial seal. A flap valve may be included on the mask 310 that isactivated by a push of a finger. The flap valve is normally slightlyopen and may be pushed closed with a finger. The user then tests theseal by inhaling slightly to confirm a good facial seal.

The materials used to form the individual components of the respirator300 are selected to have bonding compatibility with one another toensure a durable bond. For example, the outer shield portion 330, frame320, filter rim 345, optional inner shield 335, and face seal 350 may bemade of one or more plastic materials (e.g., via an injection moldingprocess) that have bonding compatibility (e.g., for overmolding).Exemplary plastic materials include but are not limited to silicone,polypropylene, Thermoplastic Silicone Vulcanizate (TPSiV), polyolefin,polyphenylsulfone, high-density polyethylene (HDPE), acrylonitrilebutadiene styrene (ABS), acrylic polymethyl methacrylate (acrylic PMMA),acetal copolymer (POM), polyetheretherketone (PEEK), and/or polybutyleneterephthalate (PBTR).

In certain embodiments, the strap 360 provides a single-sized harnessmade of a single piece of material (e.g., a silicone material).Alternatively, the strap 360 may include a two-piece harness, ormultiple pieces. The strap 360 may be available in different sizes tofit different head sizes of the user. The strap 360 is adapted to avoidthe wearer's ears to prevent hearing impairment. The strap may becoupled to the frame 320 in an integrated or detachable manner.

Respirator 300 is adapted to be lightweight for improved comfort,especially for health care workers who may wear a respirator for longdurations. For example, the respirator 300 is adapted to be lighter thanexisting elastomeric half-mask respirators due to the use of lightermaterials and fewer materials. In certain embodiments, the mask weighsbetween about 3-oz. to about 4-oz, but may weigh more or less. Therespirator 300 is adapted to have a shelf life longer than that ofexisting N95 FFRs, which is typically three to five years, due to theuse of materials that last longer. In certain embodiments, the ratedshelf life of respirator 300 is expected to be greater than fifteenyears.

Respirator 300 may include an identification tag similar to theidentification tag 105 described above in connection with FIGS. 2 and 3.Respirator 300 may be used with respirator reuse method 200 describedabove in connection with FIG. 7.

Advantages provided by embodiments of this disclosure include theability to clean, disinfect, and/or sterilize the respirator 100 as asingle unit (including filtration media) without disassembly usingeither automated reprocessing technologies found in health caresettings, other occupational settings, or homes and/or manual fieldreprocessing protocols (e.g., OSHA cleaning/disinfection guidance,disinfectant wipe, etc.) that can be performed regardless ofenvironment. The materials used to construct the respirator 100 canwithstand temperatures in excess of 50° C. These features fosterreusability especially in the health care setting, which leads to alower cost per use and reduced storage requirements compared to currentN95 FFRs used in health care settings. In addition to filteringparticles, gas/vapor absorbents (e.g., carbon) may be added to therespirator to provide VOC capture.

Another advantage is an increased lifetime of the respirator 100compared to FFRs and possibly HMERs and/or their filters, both in termsof years and total uses, because of the materials selected and theexclusion of any adhesive bonds between components that are susceptibleto premature failure, especially when repeatedly subjected to harshcleaning treatments (e.g., disinfectants, autoclaving,washer-disinfection, and/or ultrasonic bath). A longer shelf life alsoleads to lower costs for the user.

The reusable respirator 100, 300 is designed to limit bioburdenaccumulation by using smooth external surfaces. Because the mask 110(and potentially straps 161, 162) is formed from a single piece ofmaterial, creases, bond lines, and other non-smooth surfaces thattypically exist along interfaces between separate components aremitigated. This provides an advantage for cleanability, since smoothsurfaces are more readily wiped clean. These smooth surfaces helpfacilitate the use of a quick field reprocessing protocol (e.g.,disinfectant wipe) that may be applied for a limited number of reuses(e.g., five or more) between disinfection processing, which increasesthe total number of reuses (e.g., >600 total reuses). Bioburden is alsomitigated by providing an external surface shape with easy accessibilitythat reduces entrapment geometry where bioburden can accumulate. Allexternal surfaces are elastomeric and smooth making manual wipingeffective at removing contamination.

Other advantages are the use of an integrated tracking feature (e.g.,barcode, QR code, or RFID tag) for monitoring reuse. The disclosedembodiments do not require exhalation valves, which are commonly used inFFRs and HMERs and disadvantageously allow the user to breathe outcontaminants, making these devices unacceptable for use in a sterileenvironment such as an operating room. Although the disclosedembodiments are adapted for use in health care settings, they alsoprovide an improved reusable respirator option for the general public toprotect themselves against airborne particulate threats.

Features described above as well as those claimed below may be combinedin various ways without departing from the scope hereof. The followingexamples illustrate some possible, non-limiting combinations:

(A1) A reusable respiratory protection device includes a mask adaptedfor covering a portion of a user's face. The mask includes a face sealadapted to conform to a user's face around a nose and a mouth of theuser, an outer surface, at least one outer shield portion formed in theouter surface, and at least one closeable vent through the at least oneouter shield portion. The reusable respiratory protection device furtherincludes at least one particulate air filter adapted to filter at least95% of airborne particles. The at least one particulate air filter ishoused within the at least one outer shield portion. The at least onecloseable vent is adapted to direct air flow through the outer surfacefor filtering by the at least one particulate air filter. The outersurface is substantially smooth to mitigate bioburden accumulation andwettable to allow for cleaning, disinfection, or sterilization thereof.A strap is configured to secure the mask to the user's face.

(A2) For the reusable respiratory protection device denoted as (A1), thedevice may be configured to be cleaned, disinfected, and sterilizedwithout disassembly to facilitate reuse.

(A3) For the reusable respiratory protection device denoted as (A1) or(A2), the device may be configured to be sterilized by autoclaving,gamma irradiation, vaporized hydrogen peroxide, or ethylene oxide.

(A4) For the reusable respiratory protection device denoted as any of(A1) through (A3), the device may be configured to be cleaned,disinfected, or sterilized at temperatures above about 50° C. tofacilitate reuse.

(A5) For the reusable respiratory protection device denoted as any of(A1) through (A4), the mask may be a unitary structure formed of asingle piece of material.

(A6) For the reusable respiratory protection device denoted as any of(A1) through (A5), a protective pocket may be formed in each of the atleast one outer shield portion, the protective pocket being adapted toprotect the at least one particulate air filter, thereby permittingcleaning and disinfecting of the outer surface.

(A7) For the reusable respiratory protection device denoted as any of(A1) through (A6), the strap and the mask may be made of a siliconematerial that is configured to be cleaned, disinfected, and sterilizedto facilitate reuse.

(A8) For the reusable respiratory protection device denoted as any of(A1) through (A7), the at least one particulate air filter may include afilter media having at least one polytetrafluoroethylene-based layerthat is wettable and sterilizable.

(A9) For the reusable respiratory protection device denoted as any of(A1) through (A8), the at least one outer shield portion may bedeformable for enabling closure of the at least one closeable vent forfunctional testing of the face seal during use.

(A10) For the reusable respiratory protection device denoted as any of(A1) through (A9), the at least one outer shield portion may form a gapbetween the outer surface of the mask and the at least one particulateair filter that extends to the at least one closeable vent, the gapbeing adapted to provide ample space for dispersing flow of air evenlyacross the surface of the at least one particulate air filter.

(A11) For the reusable respiratory protection device denoted as any of(A1) through (A10), an inner flexible layer disposed on an inner surfaceof the at least one particulate air filter, wherein the inner flexiblelayer is located between the at least one particulate air filter and theuser during use.

(A12) For the reusable respiratory protection device denoted as any of(A1) through (A11), an identification tag may be provided, saididentification tag being adapted for scanning with a scanning device.

(A13) For the reusable respiratory protection device denoted as any of(A1) through (A12), the substantially smooth outer surface may beconfigured to allow cleaning or disinfecting of the device while beingworn by the user.

(A14) For the reusable respiratory protection device denoted as any of(A1) through (A13), the mask may have no exhalation valve such that themask is configured to maintain a sterile field in an environmentsurrounding the user during use.

(B1) A reusable respirator includes a unitary mask formed of a singlepiece of material adapted for covering a portion of a user's face. Themask includes a face seal adapted to conform to a user's face around anose and a mouth of the user, an outer surface, a first outer shieldportion formed in the outer surface, a first vent through the firstouter shield portion, a second outer shield portion formed in the outersurface, and a second vent through the second outer shield portion. Afirst particulate air filter, housed within the first outer shieldportion, is adapted to filter at least 95% of airborne particles. Asecond particulate air filter, housed within the second outer shieldportion, is adapted to filter at least 95% of airborne particles. Thefirst vent and the second vent are each adapted to direct air flow tothe first particulate air filter and the second particulate air filter,respectively. The outer surface of the mask is substantially smooth tomitigate bioburden accumulation and wettable to allow for cleaning,disinfection, or sterilization thereof.

(B2) For the reusable respirator denoted as (B1), the first outer shieldportion may be deformable for enabling closure of the first vent, andthe second outer shield portion may be deformable for enabling closureof the second vent, such that the first vent and the second vent aretemporarily closeable for functional testing of the face seal duringuse.

(C1) A method for processing a respirator for reuse includes a)providing a reusable respirator. The reusable respirator includes a maskadapted for covering a portion of a user's face. The mask includes aface seal adapted to conform to a user's face around a nose and a mouthof the user, an outer surface, at least one outer shield portion formedin the outer surface, and at least one closeable vent through the atleast one outer shield portion. At least one particulate air filter,housed within the at least one outer shield portion, is adapted tofilter at least 95% of airborne particles. The at least one closeablevent is adapted to direct air flow through the outer surface forfiltering by the at least one particulate air filter. The outer surfaceis substantially smooth and wettable to allow for disinfection thereof.A strap is configured to secure the mask to the user's face. The methodfurther includes b) using the reusable respirator in a field, and c)performing an extended reprocessing protocol.

(C2) For the method for processing a respirator denoted as (C1), themethod may comprise performing a quick field reprocessing protocol apredetermined number of times before step c).

(C3) For the method for processing a respirator denoted as any of (C1)through (C2), the respirator may further comprise an identification tag,and the method may further comprise: scanning the identification tag totrack use or the respirator, processing of the respirator, or both.

(C4) For the method for processing a respirator denoted as any of (C1)through (C3), performing the extended reprocessing protocol maycomprise: sterilizing the reusable respirator without disassembly.

It should be appreciated that, while the above disclosure has beengenerally directed to the field of respirator masks for protection fromairborne particles such as bacteria and viruses, embodiments of thisdisclosure may be directed to other fields and uses. For example,embodiments of the elastomeric half-mask N95 reusable respiratordescribed herein may be adapted to filter other types of particulatesand to provide different levels of protection, such as 99% or 99.97%minimum filtration efficiency (e.g., N99 or N100 filter classes,respectively) or different classes (P-series, R-series). Additionally,while the respirator 100, 300 is designed for compatibility with healthcare worker use, this device may be used by other industry and thegeneral population and cleaned using a home dishwasher/washing machineor other suitable methods.

Although embodiments of this disclosure have been described withreference to the illustrations in the attached drawing figures, it isnoted that equivalents may be employed and substitutions made hereinwithout departing from the scope hereof as recited in the claims.

Having thus described various embodiments, what is claimed as new anddesired to be protected by Letters Patent includes the following:
 1. Areusable respiratory protection device, comprising: a mask adapted forcovering a portion of a user's face, said mask comprising: a face sealadapted to conform to a user's face around a nose and a mouth of theuser; an outer surface; at least one outer shield portion formed as aportion of the outer surface; and at least one closeable deformable ventthrough the at least one outer shield portion; at least one particulateair filter adapted to filter at least 95% of airborne particles, said atleast one particulate air filter housed within the at least one outershield portion, wherein the at least one closeable deformable vent isadapted to direct air flow through the outer surface for filtering bythe at least one particulate air filter, wherein the outer surface issubstantially smooth to mitigate bioburden accumulation and wettable toallow for cleaning, disinfection, or sterilization thereof; and a strapconfigured to secure the mask to the user's face.
 2. The reusablerespiratory protection device of claim 1, wherein the device isconfigured to be cleaned, disinfected, and sterilized withoutdisassembly to facilitate reuse.
 3. The reusable respiratory protectiondevice of claim 2, wherein the device is further configured to besterilized by autoclaving, gamma irradiation, vaporized hydrogenperoxide, or ethylene oxide.
 4. The reusable respiratory protectiondevice of claim 1, wherein the device is configured to be cleaned,disinfected, or sterilized at temperatures above about 50° C. tofacilitate reuse.
 5. The reusable respiratory protection device of claim1, wherein the mask is a unitary structure formed of a single piece ofmaterial.
 6. The reusable respiratory protection device of claim 1,further comprising a protective pocket formed in each of the at leastone outer shield portion, the protective pocket being adapted to protectthe at least one particulate air filter, thereby permitting cleaning anddisinfecting of the outer surface.
 7. The reusable respiratoryprotection device of claim 1, wherein the strap and the mask are made ofa silicone material that is configured to be cleaned, disinfected, andsterilized to facilitate reuse.
 8. The reusable respiratory protectiondevice of claim 1, wherein the at least one particulate air filtercomprises a filter media having at least onepolytetrafluoroethylene-based layer that is wettable and sterilizable.9. The reusable respiratory protection device of claim 1, where the atleast one outer shield portion is deformable for enabling closure of theat least one closeable deformable vent for functional testing of theface seal during use.
 10. The reusable respiratory protection device ofclaim 1, wherein the at least one outer shield portion forms a gapbetween the outer surface of the mask and the at least one particulateair filter that extends to the at least one closeable deformable vent,the gap being adapted to provide ample space for dispersing flow of airevenly across the surface of the at least one particulate air filter.11. The reusable respiratory protection device of claim 1, furthercomprising an inner flexible layer disposed on an inner surface of theat least one particulate air filter, wherein the inner flexible layer islocated between the at least one particulate air filter and the userduring use.
 12. The reusable respiratory protection device of claim 1,further comprising an identification tag, said identification tag beingadapted for scanning with a scanning device.
 13. The reusablerespiratory protection device of claim 1, wherein the substantiallysmooth outer surface is configured to allow cleaning or disinfecting ofthe device while being worn by the user.
 14. The reusable respiratoryprotection device of claim 1, wherein the mask has no exhalation valvesuch that the device is configured to maintain a sterile field in anenvironment surrounding the user during use.
 15. A reusable respirator,comprising: a unitary mask formed of a single piece of material adaptedfor covering a portion of a user's face, the mask comprising: a faceseal adapted to conform to a user's face around a nose and a mouth ofthe user; an outer surface; a first outer shield portion formed as aportion of the outer surface; a first deformable vent through the firstouter shield portion; a second outer shield portion formed as a portionof the outer surface; and a second deformable vent through the secondouter shield portion; a first particulate air filter adapted to filterat least 95% of airborne particles, said first particulate air filterhoused within the first outer shield portion; and a second particulateair filter adapted to filter at least 95% of airborne particles, saidsecond particulate air filter housed within the second outer shieldportion, wherein the first deformable vent and the second deformablevent are each adapted to direct air flow to the first particulate airfilter and the second particulate air filter, respectively, wherein theouter surface of the mask is substantially smooth to mitigate bioburdenaccumulation and wettable to allow for cleaning, disinfection, orsterilization thereof.
 16. The reusable respirator of claim 15, whereinthe first outer shield portion is deformable for enabling closure of thefirst deformable vent, and the second outer shield portion is deformablefor enabling closure of the second deformable vent, such that the firstdeformable vent and the second deformable vent are temporarily closeablefor functional testing of the face seal during use.
 17. A method forprocessing a respirator for reuse, comprising: a) providing a reusablerespirator, comprising: a mask adapted for covering a portion of auser's face, said mask comprising: a face seal adapted to conform to auser's face around a nose and a mouth of the user; an outer surface; atleast one outer shield portion formed as a portion of the outer surface;and at least one closeable deformable vent through the at least oneouter shield portion; at least one particulate air filter adapted tofilter at least 95% of airborne particles, said at least one particulateair filter housed within the at least one outer shield portion, whereinthe at least one closeable deformable vent is adapted to direct air flowthrough the outer surface for filtering by the at least one particulateair filter, wherein the outer surface is substantially smooth andwettable to allow for disinfection thereof; and a strap configured tosecure the mask to the user's face; b) using the reusable respirator ina field; and c) performing an extended reprocessing protocol.
 18. Themethod for processing a respirator of claim 17, further comprising thesteps of: performing a quick field reprocessing protocol a predeterminednumber of times before step c).
 19. The method for processing arespirator of claim 17, wherein the respirator further comprises anidentification tag, the method further comprising: scanning theidentification tag to track use of the respirator, processing of therespirator, or both.
 20. The method for processing a respirator of claim17, wherein performing the extended reprocessing protocol comprisessterilizing the reusable respirator without disassembly.